Würzburg giant
The Würzburg Giant is a radar device from Telefunken and was used to locate enemy aircraft during the aerial warfare in World War II . It was an enlarged version of FuMG 62 Würzburg and, like this, used frequencies around 560 MHz ( decimeter waves ). Technically demanding was the precise control of the 11-tonne rotating part consisting of the parabolic mirror and control cabin, which was achieved with a Leonard set developed by AEG .
The stationary "giants" (camouflage names: radio transceiver FuSE 65 or radio measuring device - FuMG 65) introduced in mid-1941 were used to guide the night fighters of the Luftwaffe and were installed on the control towers of the large flak towers for fire control . The mobile Würzburg giants FuSE 65 E were mounted on railway wagons, while the fixed version for the Navy was the radio measuring device FuMO 214, which was used to control the fire of their coastal artillery (e.g. the Fjell fortress ).
Use in World War II
Use against night bombing
The air force expert and general Josef Kammhuber , commander of the night fighters , planned and implemented a line of defense made up of so-called "canopy bed" positions, which the British called the " Kammhuber Line " under the name of its organizer . The last line, more than 1000 km long, stretched from Denmark to northern France and was a sophisticated system of radio measurement positions , night fighter airfields, anti-aircraft batteries and air guards, all of which were connected by telephone to fighter control centers . The radar stations with overlapping detection areas as well as headlight positions and ready-to-launch night fighter units were intended to keep British and later American pilots away from German airspace. A central information center of several command posts of the Kammhuber line was located in the command post of the 3rd Hunting Division , a bunker facility in Schaarsbergen near Arnhem in the Netherlands . The bunker of the 3rd Hunting Division has been preserved and is used as the "Hulpdepot van het Algemeen Rijksarchief"; it is located next to the entrance to the southern entrance area of the Hoge Veluwe National Park on Koningsweg.
Incident and countermeasure
From July 1943 the Allies disrupted the effectiveness of the radar systems by throwing away tin foil strips ( chaff ). The many radio echoes initially irritated the German air defense. However, it was soon possible to use the Doppler effect to determine the speed of the located objects and to hide the slowly floating metal strips. This technique was also known as the "Würzburg solution" or, for short, "Würzlaus" , consisting of Würz von Würzburg and Laus , which was used as the code name of the former secret method. The receiver's own transmission frequency is masked out by means of a filter . Only the frequencies just above and below the own transmission frequency were received. A moving object causes a slight frequency shift via the Doppler effect. Since only the frequencies of moving objects (here: bombers) were recorded and the unchanged frequencies of the standing objects (here: slow tinfoil of the "chaff") were faded out, the bombers were suddenly clear on the display device again. Today, this procedure is standard as moving target indication (SBZ selection of moving targets) in almost all modern radar devices. This means that all "background" echoes can be faded out.
- Search area: 360 degrees
- Range:
- Search: 60–80 km
- Bearing: 50-60 km
- Transmission frequency: 560 MHz
- Bearing method: minimum bearing
Museum device in Greding (Bavaria)
The adjacent photos of a Würzburg giant were taken in Greding . Such a radar device was set up as an exhibition piece on the Kalvarienberg in the run-up to the entrance to the Defense Technical Center ( WTD 81 ). This well-preserved example still served well after the Second World War, in the USA. There the device was converted to 2.8 GHz (λ = 11 cm), as this frequency range was now mastered, with which one could also achieve a greater range. The plant did its regular service in the USA until 1957. It reached a range against flight targets of 600 km. This system was rediscovered in the Chesapeake Bay Annex in the Naval Research Laboratory Maryland / USA by a German specialist, came back to Germany in 1992, was externally repaired in 1993 and set up as a museum piece in Greding. The following text is written on the sign in front of the radar:
Radar device Würzburg-Riese (radio measuring device FuMG 65) Part of the German air defense in the Second World War 1939–1945 Classification:
Mirror diameter: 7.5 m Focal length: 153 cm Wavelength: 53 cm Frequency: 560 MHz Bandwidth: 500 kHz Pulse repetition rate: 1875 Hz Pulse width: 2 μs Antenna gain: 32 dBi DF accuracy: 0.25 degrees Receiver sensitivity: 250 kT 0 Range against flight destinations: 250 km Weight of the rotating part: 11 tons
The history of this device is also noted on the label:
1940 Start of development at Telefunken and AEG (mirror control), a total of 1500 pieces were manufactured 1948 In the spring, parts of two devices were brought to the USA and combined into one device. After upgrading to a higher frequency of 2.8 GHz, corresponding to a wavelength of 11 cm, ranges of 600 km were achieved against flight targets.
1957 End of use in the USA 1991 Discovery of the device in the Chesapeake Bay Annex of the Naval Research Lab. Maryland / USA by construction director Baudisch from the Defense Technical Service 81 (WTD 81). 1992 Handed over as a gift from the USA to the Federal Republic of Germany as part of the cooperation between American and German naval agencies. 1993 External repairs by the Wilhelmshaven naval arsenal and WTD 81. Installation at the Wehrtechnischen Dienststelle 81 for telecommunications and electronics (today information technology and electronics) in Greding / Bavaria.
Civil use and museum presentation
After the war, some of the Würzburg giants were converted into radio telescopes . Such a device was exhibited in the Deutsches Museum in Munich . It has been used for a long time and very successfully in Dwingeloo for exploring space. It can be viewed in its original design in the Military History Museum at Berlin-Gatow Airfield . A FuSE65 antenna is also preserved at the Ondřejov observatory (approx. 35 km southeast of Prague). Originally there were two antennas for measuring solar activity, the second is said to be in the Lešany Military Museum .
To the southwest of Douvres-la-Délivrande in the Calvados department in France, a complete Würzburg giant position has been preserved that can be visited.
South of Oostende , Belgium , near the Raversyde Atlantic Wall Museum, there is a giant Würzburg on a modified chassis of a railroad car of the Reichsbahn .
See also
- Radio measuring devices Overview of German radar devices in World War II
- Christian Hülsmeyer : Patent No. 165.546 of April 30, 1904: The inventor of the radio measurement / radar principle
- Robert Watson-Watt : Patent from 1919: The father of English radar development
- H2S : English on-board radar, also known as the Rotterdam device
literature
- Cajus Bekker: eyes through night and fog. Die Radar-Story , Heyne Verlag, 1988, ISBN 345300583X (Original edition: Stalling Verlag, 284 pages, 1964)
Web links
- Various information on former radio measurement positions and other units of the air intelligence service on geschichtsspuren.de
- A brief overview of the different versions of the Würzburg-Riese device
- Complete workshop book for the wireless measuring devices FuSe 62 and FuSe 65
- Radio measuring device FuMG 39 (Douvres la Délivrande / France) . The name is wrong - it is a FuMG 65 (Würzburg-Riese)
Individual evidence
- ↑ Cajus Bekker: “Eyes through night and fog. The Radar Story ”, Heyne Verlag, 1988, ISBN 978-3-453-00583-9
- ^ Directory of German Radar Equipment, War Department Tech. Manual TM E 11-219, Apr. 1945.
- ↑ The beginnings of radio astronomy in the Netherlands , bibcode : 2006JAHH .... 9 .... 3V